Bisphosphonate therapy, in general, is reported to selectively suppress osteoclast activity and thereby retarding bone resorption.36 Although it has been widely used in the clinical treatment of several bone resorption diseases including postmenopausal osteoporosis, its precise mechanism of action is not fully elucidated.36,37 Whereas some reports show that the inhibitory action of bisphosphonates on bone resorption does not involve the regulation of expression of RANKL and OPG,37 others have reported an enhanced expression of RANKL/OPG genes.38,39. This evidence concerns the gene TNFSF11 and bone resorption disease.